On April 21:
753 BC – Romulus and Remus founded Rome (traditional date).
43 BC Battle of Mutina: Mark Antony was again defeated in battle by Aulus Hirtius, who was killed.
1509 Henry VIII ascended the throne of England on the death of his father, Henry VII.
1519 Hernán Cortés landed in Veracruz.
1651 Blessed Joseph Vaz, Apostle of Ceylon, was born.
1671 John Law, Scottish economist, was born (d. 1729) .
1729 Catherine II of Russia, known as ‘Catherine the Great’, was born (d. 1796) .
1792 Tiradentes, a revolutionary leading a movement for Brazil’s independence, was hung, drawn and quartered.
1809 Two Austrian army corps were driven from Landshut by a First French Empire army led by Napoleon I of France as two French corps to the north held off the main Austrian army on the first day of the Battle of Eckmühl.
1816 Charlotte Brontë, English author, was born (d. 1855) .
1836 Texas Revolution: The Battle of San Jacinto – Republic of Texas forces under Sam Houston defeated troops under Mexican General Antonio López de Santa Anna.
1838 John Muir, Scottish environmentalist, was born (d. 1914) .
1863 Bahá’u’lláh, considered the founder of the Bahá’í Faith, declared his mission as “He whom God shall make manifest“.
1894 Norway formally adopted the Krag-Jørgensen rifle as the main arm of its armed forces, a weapon that would remain in service for almost 50 years.
1898 Spanish-American War: The U.S. Congress, recognised that a state of war existed between the United States and Spain.
1915 Anthony Quinn, Mexican-born American actor, was born (2001) .
1918 World War I: German fighter ace Manfred von Richthofen, known as “The Red Baron”, was shot down and killed over Vaux sur Somme.
1922 The first Aggie Muster was held as a remembrance for fellow Aggies who had died in the previous year.
1923 John Mortimer, English barrister and writer, was born (d. 2009) .
1926 Queen Elizabeth II was born.
1942 World War II: The most famous (and first international) Aggie Muster was held on the Philippine island of Corregidor, by Brigadier General George F. Moore (with 25 fellow Aggies who are under his command), while 1.8 million pounds of shells pounded the island over a 5 hour attack.
1952 Secretarys’ Day (now Administrative Professionals’ Day) was first celebrated.
1959 Robert Smith, British musician (The Cure), was born.
1960 Brasília, Brazil’s capital, was officially inaugurated. At 9:30 am the Three Powers of the Republic were simultaneously transferred from the old capital, Rio de Janeiro.
1960 – Founding of the Orthodox Bahá’í Faith in Washington, D.C.
1961 The first Golden Shears contest was held – won by Ivan Bowen.
1962 The Seattle World’s Fair (Century 21 Exposition) opened – the first World’s Fair in the United States since World War II.
1963 The Universal House of Justice of the Bahá’í Faith was elected for the first time.
1964 A Transit-5bn satellite failed to reach orbit after launch; as it re-entered the atmosphere, 2.1 pounds of radioactive plutonium in its SNAP RTG power source was widely dispersed.
1965 The 1964-1965 New York World’s Fair opened for its second and final season.
1966 Rastafari movement: Haile Selassie of Ethiopia visited Jamaica, an event now celebrated as Grounation Day.
1967 A few days before the general election in Greece, Colonel George Papadopoulos led a coup d’état, establishing a military regime that lasted for seven years.
1970 The Hutt River Province Principality seceded from Australia.
1975 Vietnam War: President of South Vietnam Nguyen Van Thieu fled Saigon, as Xuan Loc, the last South Vietnamese outpost blocking a direct North Vietnamese assault on Saigon, fell.
1987 Tamil Tigers were blamed for a car bomb that exploded in Colombo, killing 106 people.
1989 – Tiananmen Square Protests: In Beijing, around 100,000 students gathered in Tiananmen Square to commemorate Chinese reform leader Hu Yaobang.
1993 – The Supreme Court in La Paz, Bolivia, sentenced former dictator Luis Garcia Meza to 30 years in jail without parole for murder, theft, fraud and violating the constitution.
1994 – The first discoveries of extrasolar planets were announced by astronomer Alexander Wolszczan.
Sourced from NZ History Online & Wikipedia